Abstract:

Drag coefficient sequence Cd is obtained by solving Tiangong 1 continuous 55 days (d) GPS orbit data with different arc length. The same period solar radiation flux f 10.7 and geomagnetic index ap, Ap sequences are high and low frequency multi-wavelet decomposed. Statistical analysis results of the multilayer sliding correlation between space environmental parameters and decomposition of Cd show that lag correlation between the satellite drag coefficient sequence after wavelet decomposition and the corresponding level of  f 10.7 , Ap sequence is good. It is also verified that the Cd prediction is feasible. Prediction residuals of Cd with different regression models and different sample lengths are analyzed. The results show that the case setting sample length of 20 days and selecting  f 10.7 regression model is best. It is also show that NRLMSIS-00 model's response in the region of 350 km (Tiangong's altitude) and low-middle latitude (Tiangong's inclination) is excessive during the ascent phase of geomagnetic activity Ap and is inadequate during decline phase. Additionally, for the low-frequency decomposition sequence NRLMSIS-00 model's response is appropriate during the ascent rising phase of  f 10.7 . For the high frequency decomposition sequence, NRLMSIS-00 model's response is small-scale inadequate during the ascent phase of  f 10.7 and is excessive during the decline phase of  f 10.7 . Finally, the summary of potential use and outlook are listed; this method has an important reference value for improving the spacecraft orbit prediction accuracy.

Key words: Wavelet transformation, Drag coefficient, Lag correlation, Tiangong 1, Space environment